Primes p such that 10*p + 9 is also prime.

Terms

a(0) =2a(1) =5a(2) =7a(3) =13a(4) =17a(5) =19a(6) =23a(7) =37a(8) =41a(9) =43a(10) =47a(11) =59a(12) =61a(13) =71a(14) =73a(15) =83a(16) =101a(17) =103a(18) =127a(19) =131a(20) =139a(21) =149a(22) =157a(23) =197a(24) =199a(25) =223a(26) =233a(27) =239a(28) =257a(29) =269